On-call scenario 5: Sources

Last updated: Thursday, June 06, 2024

© Crown copyright 2017
Here are some places that you might have considered looking:
 
• BNF 
• SmPC via the emc or MHRA 
• Martindale and/or AHFS Drug Information (if you have access) 
• Your local Trust guidelines or protocols 

You are able to find some helpful advice for this scenario in these resources. 

You learn that it is generally recommended to convert the dose of modified-release carbamazepine to an equivalent immediate-release dose first, before then calculating the suppository dose.

➔ What dose of carbamazepine suppositories would you recommend for this patient?
Oral carbamazepine MR tablet 400mg twice daily is equivalent to carbamazepine tablet/suspension (immediate-release) 200mg four times daily.

Carbamazepine 100mg tablet/suspension (immediate-release) is equivalent to a carbamazepine 125mg suppository.

Therefore, an appropriate dose of a carbamazepine suppository for a patient who was taking 400mg MR BD would be 250mg QDS.  


You know that carbamazepine is a category 1 antiepileptic, that that ideally patients should not switch between brands or formulations. Reflect upon this for this patient before clicking on Next Page to see our suggestions.